This invention relates to a lens cover assembly, and, more particularly, to a lens cover assembly for binary diffractive optic lenses.
Binary diffractive optic lenses are formed by etching or molding very shallow and precise steps or grooves into the surface of a transparent optical elements. Binary diffractive optic lenses present substantial cost savings over conventional precision glass or plastic optical lenses.
However, binary diffractive optic lenses are susceptible to dirt, oil films from handling and loose particles, all of which can interfere optically with the lens. A major concern with binary diffractive optic lenses is protection of the patterned surface of the lenses.
A binary diffractive optic lens can be cleaned by conventional means such as cleansing solutions of alcohol, glycerin or water. However, these conventional cleansing means may be difficult since the surface of the binary diffractive optical lens is not flat but has microscopic grooves which must be cleaned.
Indeed, conventional cleaning means may cause problems in cleaning binary diffractive optic lenses by damaging the grooves which would interfere with operation of the lens, or by leaving remnants of the cleaning within the grooves which also would interfere with operation of the lens.
It is an object of this invention to provide a novel means to protect binary diffractive optic lenses without interfering with operation of the lenses.
It is another object of this invention to provide a lens cover assembly for binary diffractive optic lens that is more cost effective to manufacture by allowing the concurrent fabrication of large quantities of lens cover assemblies for binary diffractive optic lenses from two substrates.
It is yet another object of this invention to provide a lens cover assembly for a binary diffractive optic lens composed of two substrates which are accurately aligned with each other and bonded together.